House, who made a key 3-pointer while pouring in 11 points in 25 minutes in Game 4 against the Los Angeles Lakers, agreed to terms with the defending champions on Monday. Tony Allen, another backup guard whose development slowed when he tore ligaments in his knee during the 2006-07 season, also re-upped with the team.
Boston media reported that both players received two-year contracts.
Celtics executive director of basketball operations Danny Ainge wouldn't be specific on the financial terms of the deals, but a source told the Boston Herald that both players would be paid over $2 million per season.
The Celtics lost sixth man James Posey to free agency last week, but Monday's deals give the team a chance to return most of its key players when it goes for an 18th title next season. All five starters are under contract, and only injured Scot Pollard and aging veterans P.J. Brown and Sam Cassell are left on the market.
Although better suited as a shooting guard, House was the backup to point guard Rajon Rondo for most of the regular season, averaging 7.5 points and 19 minutes per game. After Boston signed Cassell in March, House's role was reduced. He played a total of 2 minutes over six games late in the Eastern Conference finals and early in the NBA Finals against Los Angeles.
But in Game 4 against the Lakers, House scored nine of his 11 points in the second half, including a baseline jumper with 4:07 left to give Boston its first lead of the game, 84-83. The Celtics went on to win in six games for their unprecedented 17th NBA championship.
Allen was coming into his own as a rising star, averaging 19 points in a 14-game span for the otherwise woeful Celtics in December 2006 before he blew out his knee on a meaningless breakaway dunk and missed the rest of the season. He has shown signs of returning to that form, but his minutes have largely gone elsewhere.
Information from The Associated Press was used in this report.